Nitrogen non-point sources pollution researches from purple soil cropland were carried out in Yanting agro-ecological station(CAS) watershed.Nitrogen output and transportation observation was conducted in surface runoff plots of different purple soil farmlands.Nitrogen concentrations and forms of runoff were monitored twice a month with two replicates.Nitrogen pollution load was calculated based on above observed and investigated data.Impact of non-point sources pollution of nitrogen on the environment was discussed here.Results showed,In the upland runoff,particle nitrogen contributes 35% to total nitrogen(TN).Average concentration of total nitrogen in farmland runoff was in following sequence: SNTRCS(seasonal no-tillage ridge cropping system)